When making an end-to-end join between two ends of armoured cable of this nature, and having an outside diameter of a few millimeters, welding the conductors and the sheaths together is a tricky operation that tends to leave a thickening at the join, however carefully or skilfully performed. Such a thickening is a hinderance to laying the cable and, in particular, there is a danger of it catching while the cable is being drawn through a tight space, with a consequential danger of the cable breaking at the join.
Preferred implementations of the present invention enable end-to-end welding of armoured cables that use compressed mineral insulation without producing a thickening at the join, while providing a join whose mechanical strength differs little from that of the rest of the cable. Further, the electric and dielectric characteristics of the cable are substantially unaltered at the join.